Improvement in railroad-car springs



UNITED STATES PATENT ()FFICE.

JAMES W. EVANS, OF NEW YORK, N. Y.

IMPROVEMENT IN RAILROAD-CAR SPRINGS.

Specification forming part of Letters Patent No. 37,283, dated January 6, 1863.

To all whom it may concern/.-

Be it known that I, JAMES W. EVANS, of the city, county, and State of New York, mechanical engineer, have invented new and useful Improvements in Railroad-Oar Springs; and I do hereby declare that the following is a full and exact description of my said invention and improvements, reference being had to the drawings accompanying and making part of this specification.

Figure I of the drawings represents an elevation or exterior of the case or box of the spring and of the base and convex surface upon which the lower series or group of plates rests. Fig. II represents a vertical section through the center of the spring when the spring is at rest. Fig. III represents the same section when the first or lower series of plates or springs only are acted upon by the load or pressure, the others being at rest. Fig. IV represents the same section, with all the groups or series of plates or springs bent down to their extreme action by the load or pressure. Figs. V and VI are surface views of the top and bottom of the spring.

In all the figures the same letters represent the same parts.

The nature of my invention consists in the arrangement of a series of plate-springs in the form of flat disks in groups of successivelyincreasing numbers of plates, from the bottom group, in combination with intermediate separating and supporting inelastic disks of a novel and peculiar form, having ferrules, around which the groups of elastic disks are placed, and the whole inclosed by a sliding cover or case, by which they are held together and made to operate, and so as thereby to get a progressive elastic action according to the load, and so as to prevent any binding, gripping, or direct vertical strain across the plane of the .elastic plates.

In the drawings, Figs. II, III, IV, a a a a represent cast-steel. plate-springs, all concentric, and all of the same diameter and dimensions, in the form of flat disks. openings in the center for arranging them upon the ferrules upon the supporting and intermediate plates hereinafter described.

I) is the base upon which the spring stands, having its upper surface convex, a ferrule, e, at the center, and underneath a recess for the They all have head of the bolt, and sufficiently deep for the play of the bolt, if one is used.

c e c are inelastic intermediate and supportin g plates, open at the centers, around which openings are ferrules e, of sufficient height above the upper surface to hold the group of elastic plates or springs belonging to it. The upper surfaces of the disks 0 c c are convex, and the lower concave. Upon the peripheries are lips or rims c, projecting downward sufficiently to inclose the group of elastic plates immediately underit. Excepting in the length of this projecting lip or rim, these intermediate plates all have the same form and size and diameter, their convex and concaved surfaces being exactly similar. Near the angle formed by the lip the interior lower face of the plate 0 is cut away in the shape of an ogee or cyma curve, as seen in Figs. II, III, VI at c. The form given to this part of the intermediate plate performs a very important function in preventing any sharp cross action or strain upon the outer edge of the spring-plates, by which they would otherwise be in danger of fracture under the constant action and pressure of the load.

D is a cover or cylindrical box, made so as to shut down upon the parts before described and to hold them together, so that the differ ent parts will act with facility, and at the same time hold them in their places without the necessity of a bolt or other fastening. The inter'ior surface of the cover D is recessed, d, to fit close to c c, and to allow these parts that proper action, and. the surface under d of the top is concave, and cut away, a", precisely similar to the corresponding surfaces of the intermediate plates, 0 c.

When the spring is to be put together for use, the first group of plates, consisting of two elastic disks, are placed over the ferrule upon the base b then the inelastic intermediate plate, 0 then the second group of elastic plates, consisting of four, upon the ferrule of the last mentioned intermediate plate; then the next intermediate plate, and upon this the next group of elastic plates, consisting of six; then another intermediate plate, and upon this the next and last group of elastic plates, consisting of eight, and over all the cover D. When not in use, a bolt may be used to hold the parts together for convenience, but when under the car there is no necessity for a bolt. Under a light pressure the lower and last group of plates will be acted upon, and as the load and pressure increase the action will proceed successively to the next group, until all are exerting their elastic force. The plates being arranged upon the ferrules without fastening, and without being gripped in any part, and supported throughout their whole under surfaces when exerted to their full action, and the peculiar form given to the bearings at 0, prevents any cross-strain, and removes almost entirely any liability to wear or fracture in any one part more than another.

Although I have named two, four, six, and eight as the number of plates in the groups successively, I do not confine myself to this precise number and proportion, but give this asthe'inost convenient, and,'perhaps, the best.

I am aware of the use of steel plates in the form of disks, and with intermediate inelastic p1ate's,in great variety of forms, and of a sliding "case or c'over; but I am not aware of the use'of an intermediate separating and sustaining inelastic plate of the form and with the features of the plate 0, herein described; nor

am'I aware that the disk spring plates have been arranged loose at their centers without nut or fixed fastenings, so as to have no point of a direct cross action or strain upon the metal, and'at the same time having the plates supported throughout when at their full tension each group, and the ogee recess 0 near the angle.

2. Suspending andholding the elastic plates together at the centers and edges without fixed fastenings, as described.

3. The combining and arranging the box or cover D with the other parts, so as to hold together the whole as a complete spring with or without a bolt and without any fixed fastening of the working parts.

4.. The combining and arranging the elastic and non-elastic plates with the above-dcscribed manner of hanging the elastic platesloose at their centers, thereby rendering fracture or tearing of the plates almost impossible. JAMES W. EVANS.

W'itnesses V J. B. STAPLES,

A. H. PALMER. 

